4 * Copyright IBM, Corp. 2007
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qemu-common.h"
18 #include "qemu/error-report.h"
20 #include "hw/block/block.h"
21 #include "sysemu/blockdev.h"
22 #include "hw/virtio/virtio-blk.h"
23 #include "dataplane/virtio-blk.h"
24 #include "scsi/constants.h"
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/virtio/virtio-access.h"
31 /* We don't support discard yet, hide associated config fields. */
32 #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
35 static void virtio_blk_init_request(VirtIOBlock
*s
, VirtQueue
*vq
,
46 static void virtio_blk_free_request(VirtIOBlockReq
*req
)
51 static void virtio_blk_req_complete(VirtIOBlockReq
*req
, unsigned char status
)
53 VirtIOBlock
*s
= req
->dev
;
54 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
56 trace_virtio_blk_req_complete(vdev
, req
, status
);
58 stb_p(&req
->in
->status
, status
);
59 virtqueue_push(req
->vq
, &req
->elem
, req
->in_len
);
60 if (s
->dataplane_started
&& !s
->dataplane_disabled
) {
61 virtio_blk_data_plane_notify(s
->dataplane
, req
->vq
);
63 virtio_notify(vdev
, req
->vq
);
67 static int virtio_blk_handle_rw_error(VirtIOBlockReq
*req
, int error
,
68 bool is_read
, bool acct_failed
)
70 VirtIOBlock
*s
= req
->dev
;
71 BlockErrorAction action
= blk_get_error_action(s
->blk
, is_read
, error
);
73 if (action
== BLOCK_ERROR_ACTION_STOP
) {
74 /* Break the link as the next request is going to be parsed from the
75 * ring again. Otherwise we may end up doing a double completion! */
79 } else if (action
== BLOCK_ERROR_ACTION_REPORT
) {
80 virtio_blk_req_complete(req
, VIRTIO_BLK_S_IOERR
);
82 block_acct_failed(blk_get_stats(s
->blk
), &req
->acct
);
84 virtio_blk_free_request(req
);
87 blk_error_action(s
->blk
, action
, is_read
, error
);
88 return action
!= BLOCK_ERROR_ACTION_IGNORE
;
91 static void virtio_blk_rw_complete(void *opaque
, int ret
)
93 VirtIOBlockReq
*next
= opaque
;
94 VirtIOBlock
*s
= next
->dev
;
95 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
97 aio_context_acquire(blk_get_aio_context(s
->conf
.conf
.blk
));
99 VirtIOBlockReq
*req
= next
;
101 trace_virtio_blk_rw_complete(vdev
, req
, ret
);
103 if (req
->qiov
.nalloc
!= -1) {
104 /* If nalloc is != -1 req->qiov is a local copy of the original
105 * external iovec. It was allocated in submit_requests to be
106 * able to merge requests. */
107 qemu_iovec_destroy(&req
->qiov
);
111 int p
= virtio_ldl_p(VIRTIO_DEVICE(req
->dev
), &req
->out
.type
);
112 bool is_read
= !(p
& VIRTIO_BLK_T_OUT
);
113 /* Note that memory may be dirtied on read failure. If the
114 * virtio request is not completed here, as is the case for
115 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied
116 * correctly during live migration. While this is ugly,
117 * it is acceptable because the device is free to write to
118 * the memory until the request is completed (which will
119 * happen on the other side of the migration).
121 if (virtio_blk_handle_rw_error(req
, -ret
, is_read
, true)) {
126 virtio_blk_req_complete(req
, VIRTIO_BLK_S_OK
);
127 block_acct_done(blk_get_stats(req
->dev
->blk
), &req
->acct
);
128 virtio_blk_free_request(req
);
130 aio_context_release(blk_get_aio_context(s
->conf
.conf
.blk
));
133 static void virtio_blk_flush_complete(void *opaque
, int ret
)
135 VirtIOBlockReq
*req
= opaque
;
136 VirtIOBlock
*s
= req
->dev
;
138 aio_context_acquire(blk_get_aio_context(s
->conf
.conf
.blk
));
140 if (virtio_blk_handle_rw_error(req
, -ret
, 0, true)) {
145 virtio_blk_req_complete(req
, VIRTIO_BLK_S_OK
);
146 block_acct_done(blk_get_stats(s
->blk
), &req
->acct
);
147 virtio_blk_free_request(req
);
150 aio_context_release(blk_get_aio_context(s
->conf
.conf
.blk
));
157 struct sg_io_hdr hdr
;
158 } VirtIOBlockIoctlReq
;
160 static void virtio_blk_ioctl_complete(void *opaque
, int status
)
162 VirtIOBlockIoctlReq
*ioctl_req
= opaque
;
163 VirtIOBlockReq
*req
= ioctl_req
->req
;
164 VirtIOBlock
*s
= req
->dev
;
165 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
166 struct virtio_scsi_inhdr
*scsi
;
167 struct sg_io_hdr
*hdr
;
169 scsi
= (void *)req
->elem
.in_sg
[req
->elem
.in_num
- 2].iov_base
;
172 status
= VIRTIO_BLK_S_UNSUPP
;
173 virtio_stl_p(vdev
, &scsi
->errors
, 255);
177 hdr
= &ioctl_req
->hdr
;
179 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
180 * clear the masked_status field [hence status gets cleared too, see
181 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
182 * status has occurred. However they do set DRIVER_SENSE in driver_status
183 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
185 if (hdr
->status
== 0 && hdr
->sb_len_wr
> 0) {
186 hdr
->status
= CHECK_CONDITION
;
189 virtio_stl_p(vdev
, &scsi
->errors
,
190 hdr
->status
| (hdr
->msg_status
<< 8) |
191 (hdr
->host_status
<< 16) | (hdr
->driver_status
<< 24));
192 virtio_stl_p(vdev
, &scsi
->residual
, hdr
->resid
);
193 virtio_stl_p(vdev
, &scsi
->sense_len
, hdr
->sb_len_wr
);
194 virtio_stl_p(vdev
, &scsi
->data_len
, hdr
->dxfer_len
);
197 aio_context_acquire(blk_get_aio_context(s
->conf
.conf
.blk
));
198 virtio_blk_req_complete(req
, status
);
199 virtio_blk_free_request(req
);
200 aio_context_release(blk_get_aio_context(s
->conf
.conf
.blk
));
206 static VirtIOBlockReq
*virtio_blk_get_request(VirtIOBlock
*s
, VirtQueue
*vq
)
208 VirtIOBlockReq
*req
= virtqueue_pop(vq
, sizeof(VirtIOBlockReq
));
211 virtio_blk_init_request(s
, vq
, req
);
216 static int virtio_blk_handle_scsi_req(VirtIOBlockReq
*req
)
218 int status
= VIRTIO_BLK_S_OK
;
219 struct virtio_scsi_inhdr
*scsi
= NULL
;
220 VirtIODevice
*vdev
= VIRTIO_DEVICE(req
->dev
);
221 VirtQueueElement
*elem
= &req
->elem
;
222 VirtIOBlock
*blk
= req
->dev
;
226 VirtIOBlockIoctlReq
*ioctl_req
;
231 * We require at least one output segment each for the virtio_blk_outhdr
232 * and the SCSI command block.
234 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
235 * and the sense buffer pointer in the input segments.
237 if (elem
->out_num
< 2 || elem
->in_num
< 3) {
238 status
= VIRTIO_BLK_S_IOERR
;
243 * The scsi inhdr is placed in the second-to-last input segment, just
244 * before the regular inhdr.
246 scsi
= (void *)elem
->in_sg
[elem
->in_num
- 2].iov_base
;
248 if (!virtio_has_feature(blk
->host_features
, VIRTIO_BLK_F_SCSI
)) {
249 status
= VIRTIO_BLK_S_UNSUPP
;
254 * No support for bidirection commands yet.
256 if (elem
->out_num
> 2 && elem
->in_num
> 3) {
257 status
= VIRTIO_BLK_S_UNSUPP
;
262 ioctl_req
= g_new0(VirtIOBlockIoctlReq
, 1);
263 ioctl_req
->req
= req
;
264 ioctl_req
->hdr
.interface_id
= 'S';
265 ioctl_req
->hdr
.cmd_len
= elem
->out_sg
[1].iov_len
;
266 ioctl_req
->hdr
.cmdp
= elem
->out_sg
[1].iov_base
;
267 ioctl_req
->hdr
.dxfer_len
= 0;
269 if (elem
->out_num
> 2) {
271 * If there are more than the minimally required 2 output segments
272 * there is write payload starting from the third iovec.
274 ioctl_req
->hdr
.dxfer_direction
= SG_DXFER_TO_DEV
;
275 ioctl_req
->hdr
.iovec_count
= elem
->out_num
- 2;
277 for (i
= 0; i
< ioctl_req
->hdr
.iovec_count
; i
++) {
278 ioctl_req
->hdr
.dxfer_len
+= elem
->out_sg
[i
+ 2].iov_len
;
281 ioctl_req
->hdr
.dxferp
= elem
->out_sg
+ 2;
283 } else if (elem
->in_num
> 3) {
285 * If we have more than 3 input segments the guest wants to actually
288 ioctl_req
->hdr
.dxfer_direction
= SG_DXFER_FROM_DEV
;
289 ioctl_req
->hdr
.iovec_count
= elem
->in_num
- 3;
290 for (i
= 0; i
< ioctl_req
->hdr
.iovec_count
; i
++) {
291 ioctl_req
->hdr
.dxfer_len
+= elem
->in_sg
[i
].iov_len
;
294 ioctl_req
->hdr
.dxferp
= elem
->in_sg
;
297 * Some SCSI commands don't actually transfer any data.
299 ioctl_req
->hdr
.dxfer_direction
= SG_DXFER_NONE
;
302 ioctl_req
->hdr
.sbp
= elem
->in_sg
[elem
->in_num
- 3].iov_base
;
303 ioctl_req
->hdr
.mx_sb_len
= elem
->in_sg
[elem
->in_num
- 3].iov_len
;
305 acb
= blk_aio_ioctl(blk
->blk
, SG_IO
, &ioctl_req
->hdr
,
306 virtio_blk_ioctl_complete
, ioctl_req
);
309 status
= VIRTIO_BLK_S_UNSUPP
;
318 /* Just put anything nonzero so that the ioctl fails in the guest. */
320 virtio_stl_p(vdev
, &scsi
->errors
, 255);
325 static void virtio_blk_handle_scsi(VirtIOBlockReq
*req
)
329 status
= virtio_blk_handle_scsi_req(req
);
330 if (status
!= -EINPROGRESS
) {
331 virtio_blk_req_complete(req
, status
);
332 virtio_blk_free_request(req
);
336 static inline void submit_requests(BlockBackend
*blk
, MultiReqBuffer
*mrb
,
337 int start
, int num_reqs
, int niov
)
339 QEMUIOVector
*qiov
= &mrb
->reqs
[start
]->qiov
;
340 int64_t sector_num
= mrb
->reqs
[start
]->sector_num
;
341 bool is_write
= mrb
->is_write
;
345 struct iovec
*tmp_iov
= qiov
->iov
;
346 int tmp_niov
= qiov
->niov
;
348 /* mrb->reqs[start]->qiov was initialized from external so we can't
349 * modify it here. We need to initialize it locally and then add the
350 * external iovecs. */
351 qemu_iovec_init(qiov
, niov
);
353 for (i
= 0; i
< tmp_niov
; i
++) {
354 qemu_iovec_add(qiov
, tmp_iov
[i
].iov_base
, tmp_iov
[i
].iov_len
);
357 for (i
= start
+ 1; i
< start
+ num_reqs
; i
++) {
358 qemu_iovec_concat(qiov
, &mrb
->reqs
[i
]->qiov
, 0,
359 mrb
->reqs
[i
]->qiov
.size
);
360 mrb
->reqs
[i
- 1]->mr_next
= mrb
->reqs
[i
];
363 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb
->reqs
[start
]->dev
),
364 mrb
, start
, num_reqs
,
365 sector_num
<< BDRV_SECTOR_BITS
,
366 qiov
->size
, is_write
);
367 block_acct_merge_done(blk_get_stats(blk
),
368 is_write
? BLOCK_ACCT_WRITE
: BLOCK_ACCT_READ
,
373 blk_aio_pwritev(blk
, sector_num
<< BDRV_SECTOR_BITS
, qiov
, 0,
374 virtio_blk_rw_complete
, mrb
->reqs
[start
]);
376 blk_aio_preadv(blk
, sector_num
<< BDRV_SECTOR_BITS
, qiov
, 0,
377 virtio_blk_rw_complete
, mrb
->reqs
[start
]);
381 static int multireq_compare(const void *a
, const void *b
)
383 const VirtIOBlockReq
*req1
= *(VirtIOBlockReq
**)a
,
384 *req2
= *(VirtIOBlockReq
**)b
;
387 * Note that we can't simply subtract sector_num1 from sector_num2
388 * here as that could overflow the return value.
390 if (req1
->sector_num
> req2
->sector_num
) {
392 } else if (req1
->sector_num
< req2
->sector_num
) {
399 static void virtio_blk_submit_multireq(BlockBackend
*blk
, MultiReqBuffer
*mrb
)
401 int i
= 0, start
= 0, num_reqs
= 0, niov
= 0, nb_sectors
= 0;
402 uint32_t max_transfer
;
403 int64_t sector_num
= 0;
405 if (mrb
->num_reqs
== 1) {
406 submit_requests(blk
, mrb
, 0, 1, -1);
411 max_transfer
= blk_get_max_transfer(mrb
->reqs
[0]->dev
->blk
);
413 qsort(mrb
->reqs
, mrb
->num_reqs
, sizeof(*mrb
->reqs
),
416 for (i
= 0; i
< mrb
->num_reqs
; i
++) {
417 VirtIOBlockReq
*req
= mrb
->reqs
[i
];
420 * NOTE: We cannot merge the requests in below situations:
421 * 1. requests are not sequential
422 * 2. merge would exceed maximum number of IOVs
423 * 3. merge would exceed maximum transfer length of backend device
425 if (sector_num
+ nb_sectors
!= req
->sector_num
||
426 niov
> blk_get_max_iov(blk
) - req
->qiov
.niov
||
427 req
->qiov
.size
> max_transfer
||
428 nb_sectors
> (max_transfer
-
429 req
->qiov
.size
) / BDRV_SECTOR_SIZE
) {
430 submit_requests(blk
, mrb
, start
, num_reqs
, niov
);
436 sector_num
= req
->sector_num
;
437 nb_sectors
= niov
= 0;
441 nb_sectors
+= req
->qiov
.size
/ BDRV_SECTOR_SIZE
;
442 niov
+= req
->qiov
.niov
;
446 submit_requests(blk
, mrb
, start
, num_reqs
, niov
);
450 static void virtio_blk_handle_flush(VirtIOBlockReq
*req
, MultiReqBuffer
*mrb
)
452 block_acct_start(blk_get_stats(req
->dev
->blk
), &req
->acct
, 0,
456 * Make sure all outstanding writes are posted to the backing device.
458 if (mrb
->is_write
&& mrb
->num_reqs
> 0) {
459 virtio_blk_submit_multireq(req
->dev
->blk
, mrb
);
461 blk_aio_flush(req
->dev
->blk
, virtio_blk_flush_complete
, req
);
464 static bool virtio_blk_sect_range_ok(VirtIOBlock
*dev
,
465 uint64_t sector
, size_t size
)
467 uint64_t nb_sectors
= size
>> BDRV_SECTOR_BITS
;
468 uint64_t total_sectors
;
470 if (nb_sectors
> BDRV_REQUEST_MAX_SECTORS
) {
473 if (sector
& dev
->sector_mask
) {
476 if (size
% dev
->conf
.conf
.logical_block_size
) {
479 blk_get_geometry(dev
->blk
, &total_sectors
);
480 if (sector
> total_sectors
|| nb_sectors
> total_sectors
- sector
) {
486 static int virtio_blk_handle_request(VirtIOBlockReq
*req
, MultiReqBuffer
*mrb
)
489 struct iovec
*in_iov
= req
->elem
.in_sg
;
490 struct iovec
*out_iov
= req
->elem
.out_sg
;
491 unsigned in_num
= req
->elem
.in_num
;
492 unsigned out_num
= req
->elem
.out_num
;
493 VirtIOBlock
*s
= req
->dev
;
494 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
496 if (req
->elem
.out_num
< 1 || req
->elem
.in_num
< 1) {
497 virtio_error(vdev
, "virtio-blk missing headers");
501 if (unlikely(iov_to_buf(out_iov
, out_num
, 0, &req
->out
,
502 sizeof(req
->out
)) != sizeof(req
->out
))) {
503 virtio_error(vdev
, "virtio-blk request outhdr too short");
507 iov_discard_front(&out_iov
, &out_num
, sizeof(req
->out
));
509 if (in_iov
[in_num
- 1].iov_len
< sizeof(struct virtio_blk_inhdr
)) {
510 virtio_error(vdev
, "virtio-blk request inhdr too short");
514 /* We always touch the last byte, so just see how big in_iov is. */
515 req
->in_len
= iov_size(in_iov
, in_num
);
516 req
->in
= (void *)in_iov
[in_num
- 1].iov_base
517 + in_iov
[in_num
- 1].iov_len
518 - sizeof(struct virtio_blk_inhdr
);
519 iov_discard_back(in_iov
, &in_num
, sizeof(struct virtio_blk_inhdr
));
521 type
= virtio_ldl_p(vdev
, &req
->out
.type
);
523 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER
524 * is an optional flag. Although a guest should not send this flag if
525 * not negotiated we ignored it in the past. So keep ignoring it. */
526 switch (type
& ~(VIRTIO_BLK_T_OUT
| VIRTIO_BLK_T_BARRIER
)) {
527 case VIRTIO_BLK_T_IN
:
529 bool is_write
= type
& VIRTIO_BLK_T_OUT
;
530 req
->sector_num
= virtio_ldq_p(vdev
, &req
->out
.sector
);
533 qemu_iovec_init_external(&req
->qiov
, out_iov
, out_num
);
534 trace_virtio_blk_handle_write(vdev
, req
, req
->sector_num
,
535 req
->qiov
.size
/ BDRV_SECTOR_SIZE
);
537 qemu_iovec_init_external(&req
->qiov
, in_iov
, in_num
);
538 trace_virtio_blk_handle_read(vdev
, req
, req
->sector_num
,
539 req
->qiov
.size
/ BDRV_SECTOR_SIZE
);
542 if (!virtio_blk_sect_range_ok(s
, req
->sector_num
, req
->qiov
.size
)) {
543 virtio_blk_req_complete(req
, VIRTIO_BLK_S_IOERR
);
544 block_acct_invalid(blk_get_stats(s
->blk
),
545 is_write
? BLOCK_ACCT_WRITE
: BLOCK_ACCT_READ
);
546 virtio_blk_free_request(req
);
550 block_acct_start(blk_get_stats(s
->blk
), &req
->acct
, req
->qiov
.size
,
551 is_write
? BLOCK_ACCT_WRITE
: BLOCK_ACCT_READ
);
553 /* merge would exceed maximum number of requests or IO direction
555 if (mrb
->num_reqs
> 0 && (mrb
->num_reqs
== VIRTIO_BLK_MAX_MERGE_REQS
||
556 is_write
!= mrb
->is_write
||
557 !s
->conf
.request_merging
)) {
558 virtio_blk_submit_multireq(s
->blk
, mrb
);
561 assert(mrb
->num_reqs
< VIRTIO_BLK_MAX_MERGE_REQS
);
562 mrb
->reqs
[mrb
->num_reqs
++] = req
;
563 mrb
->is_write
= is_write
;
566 case VIRTIO_BLK_T_FLUSH
:
567 virtio_blk_handle_flush(req
, mrb
);
569 case VIRTIO_BLK_T_SCSI_CMD
:
570 virtio_blk_handle_scsi(req
);
572 case VIRTIO_BLK_T_GET_ID
:
575 * NB: per existing s/n string convention the string is
576 * terminated by '\0' only when shorter than buffer.
578 const char *serial
= s
->conf
.serial
? s
->conf
.serial
: "";
579 size_t size
= MIN(strlen(serial
) + 1,
580 MIN(iov_size(in_iov
, in_num
),
581 VIRTIO_BLK_ID_BYTES
));
582 iov_from_buf(in_iov
, in_num
, 0, serial
, size
);
583 virtio_blk_req_complete(req
, VIRTIO_BLK_S_OK
);
584 virtio_blk_free_request(req
);
588 virtio_blk_req_complete(req
, VIRTIO_BLK_S_UNSUPP
);
589 virtio_blk_free_request(req
);
594 bool virtio_blk_handle_vq(VirtIOBlock
*s
, VirtQueue
*vq
)
597 MultiReqBuffer mrb
= {};
598 bool progress
= false;
600 aio_context_acquire(blk_get_aio_context(s
->blk
));
604 virtio_queue_set_notification(vq
, 0);
606 while ((req
= virtio_blk_get_request(s
, vq
))) {
608 if (virtio_blk_handle_request(req
, &mrb
)) {
609 virtqueue_detach_element(req
->vq
, &req
->elem
, 0);
610 virtio_blk_free_request(req
);
615 virtio_queue_set_notification(vq
, 1);
616 } while (!virtio_queue_empty(vq
));
619 virtio_blk_submit_multireq(s
->blk
, &mrb
);
622 blk_io_unplug(s
->blk
);
623 aio_context_release(blk_get_aio_context(s
->blk
));
627 static void virtio_blk_handle_output_do(VirtIOBlock
*s
, VirtQueue
*vq
)
629 virtio_blk_handle_vq(s
, vq
);
632 static void virtio_blk_handle_output(VirtIODevice
*vdev
, VirtQueue
*vq
)
634 VirtIOBlock
*s
= (VirtIOBlock
*)vdev
;
637 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
638 * dataplane here instead of waiting for .set_status().
640 virtio_device_start_ioeventfd(vdev
);
641 if (!s
->dataplane_disabled
) {
645 virtio_blk_handle_output_do(s
, vq
);
648 static void virtio_blk_dma_restart_bh(void *opaque
)
650 VirtIOBlock
*s
= opaque
;
651 VirtIOBlockReq
*req
= s
->rq
;
652 MultiReqBuffer mrb
= {};
654 qemu_bh_delete(s
->bh
);
659 aio_context_acquire(blk_get_aio_context(s
->conf
.conf
.blk
));
661 VirtIOBlockReq
*next
= req
->next
;
662 if (virtio_blk_handle_request(req
, &mrb
)) {
663 /* Device is now broken and won't do any processing until it gets
664 * reset. Already queued requests will be lost: let's purge them.
668 virtqueue_detach_element(req
->vq
, &req
->elem
, 0);
669 virtio_blk_free_request(req
);
678 virtio_blk_submit_multireq(s
->blk
, &mrb
);
680 aio_context_release(blk_get_aio_context(s
->conf
.conf
.blk
));
683 static void virtio_blk_dma_restart_cb(void *opaque
, int running
,
686 VirtIOBlock
*s
= opaque
;
693 s
->bh
= aio_bh_new(blk_get_aio_context(s
->conf
.conf
.blk
),
694 virtio_blk_dma_restart_bh
, s
);
695 qemu_bh_schedule(s
->bh
);
699 static void virtio_blk_reset(VirtIODevice
*vdev
)
701 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
705 ctx
= blk_get_aio_context(s
->blk
);
706 aio_context_acquire(ctx
);
709 /* We drop queued requests after blk_drain() because blk_drain() itself can
714 virtqueue_detach_element(req
->vq
, &req
->elem
, 0);
715 virtio_blk_free_request(req
);
718 aio_context_release(ctx
);
720 assert(!s
->dataplane_started
);
721 blk_set_enable_write_cache(s
->blk
, s
->original_wce
);
724 /* coalesce internal state, copy to pci i/o region 0
726 static void virtio_blk_update_config(VirtIODevice
*vdev
, uint8_t *config
)
728 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
729 BlockConf
*conf
= &s
->conf
.conf
;
730 struct virtio_blk_config blkcfg
;
733 int blk_size
= conf
->logical_block_size
;
735 blk_get_geometry(s
->blk
, &capacity
);
736 memset(&blkcfg
, 0, sizeof(blkcfg
));
737 virtio_stq_p(vdev
, &blkcfg
.capacity
, capacity
);
738 virtio_stl_p(vdev
, &blkcfg
.seg_max
, 128 - 2);
739 virtio_stw_p(vdev
, &blkcfg
.geometry
.cylinders
, conf
->cyls
);
740 virtio_stl_p(vdev
, &blkcfg
.blk_size
, blk_size
);
741 virtio_stw_p(vdev
, &blkcfg
.min_io_size
, conf
->min_io_size
/ blk_size
);
742 virtio_stw_p(vdev
, &blkcfg
.opt_io_size
, conf
->opt_io_size
/ blk_size
);
743 blkcfg
.geometry
.heads
= conf
->heads
;
745 * We must ensure that the block device capacity is a multiple of
746 * the logical block size. If that is not the case, let's use
747 * sector_mask to adopt the geometry to have a correct picture.
748 * For those devices where the capacity is ok for the given geometry
749 * we don't touch the sector value of the geometry, since some devices
750 * (like s390 dasd) need a specific value. Here the capacity is already
751 * cyls*heads*secs*blk_size and the sector value is not block size
752 * divided by 512 - instead it is the amount of blk_size blocks
753 * per track (cylinder).
755 length
= blk_getlength(s
->blk
);
756 if (length
> 0 && length
/ conf
->heads
/ conf
->secs
% blk_size
) {
757 blkcfg
.geometry
.sectors
= conf
->secs
& ~s
->sector_mask
;
759 blkcfg
.geometry
.sectors
= conf
->secs
;
762 blkcfg
.physical_block_exp
= get_physical_block_exp(conf
);
763 blkcfg
.alignment_offset
= 0;
764 blkcfg
.wce
= blk_enable_write_cache(s
->blk
);
765 virtio_stw_p(vdev
, &blkcfg
.num_queues
, s
->conf
.num_queues
);
766 memcpy(config
, &blkcfg
, VIRTIO_BLK_CFG_SIZE
);
767 QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE
> sizeof(blkcfg
));
770 static void virtio_blk_set_config(VirtIODevice
*vdev
, const uint8_t *config
)
772 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
773 struct virtio_blk_config blkcfg
;
775 memcpy(&blkcfg
, config
, VIRTIO_BLK_CFG_SIZE
);
776 QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE
> sizeof(blkcfg
));
778 aio_context_acquire(blk_get_aio_context(s
->blk
));
779 blk_set_enable_write_cache(s
->blk
, blkcfg
.wce
!= 0);
780 aio_context_release(blk_get_aio_context(s
->blk
));
783 static uint64_t virtio_blk_get_features(VirtIODevice
*vdev
, uint64_t features
,
786 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
788 /* Firstly sync all virtio-blk possible supported features */
789 features
|= s
->host_features
;
791 virtio_add_feature(&features
, VIRTIO_BLK_F_SEG_MAX
);
792 virtio_add_feature(&features
, VIRTIO_BLK_F_GEOMETRY
);
793 virtio_add_feature(&features
, VIRTIO_BLK_F_TOPOLOGY
);
794 virtio_add_feature(&features
, VIRTIO_BLK_F_BLK_SIZE
);
795 if (virtio_has_feature(features
, VIRTIO_F_VERSION_1
)) {
796 if (virtio_has_feature(s
->host_features
, VIRTIO_BLK_F_SCSI
)) {
797 error_setg(errp
, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
801 virtio_clear_feature(&features
, VIRTIO_F_ANY_LAYOUT
);
802 virtio_add_feature(&features
, VIRTIO_BLK_F_SCSI
);
805 if (blk_enable_write_cache(s
->blk
)) {
806 virtio_add_feature(&features
, VIRTIO_BLK_F_WCE
);
808 if (blk_is_read_only(s
->blk
)) {
809 virtio_add_feature(&features
, VIRTIO_BLK_F_RO
);
811 if (s
->conf
.num_queues
> 1) {
812 virtio_add_feature(&features
, VIRTIO_BLK_F_MQ
);
818 static void virtio_blk_set_status(VirtIODevice
*vdev
, uint8_t status
)
820 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
822 if (!(status
& (VIRTIO_CONFIG_S_DRIVER
| VIRTIO_CONFIG_S_DRIVER_OK
))) {
823 assert(!s
->dataplane_started
);
826 if (!(status
& VIRTIO_CONFIG_S_DRIVER_OK
)) {
830 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
831 * cache flushes. Thus, the "auto writethrough" behavior is never
832 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature.
833 * Leaving it enabled would break the following sequence:
835 * Guest started with "-drive cache=writethrough"
836 * Guest sets status to 0
837 * Guest sets DRIVER bit in status field
838 * Guest reads host features (WCE=0, CONFIG_WCE=1)
839 * Guest writes guest features (WCE=0, CONFIG_WCE=1)
840 * Guest writes 1 to the WCE configuration field (writeback mode)
841 * Guest sets DRIVER_OK bit in status field
843 * s->blk would erroneously be placed in writethrough mode.
845 if (!virtio_vdev_has_feature(vdev
, VIRTIO_BLK_F_CONFIG_WCE
)) {
846 aio_context_acquire(blk_get_aio_context(s
->blk
));
847 blk_set_enable_write_cache(s
->blk
,
848 virtio_vdev_has_feature(vdev
,
850 aio_context_release(blk_get_aio_context(s
->blk
));
854 static void virtio_blk_save_device(VirtIODevice
*vdev
, QEMUFile
*f
)
856 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
857 VirtIOBlockReq
*req
= s
->rq
;
860 qemu_put_sbyte(f
, 1);
862 if (s
->conf
.num_queues
> 1) {
863 qemu_put_be32(f
, virtio_get_queue_index(req
->vq
));
866 qemu_put_virtqueue_element(f
, &req
->elem
);
869 qemu_put_sbyte(f
, 0);
872 static int virtio_blk_load_device(VirtIODevice
*vdev
, QEMUFile
*f
,
875 VirtIOBlock
*s
= VIRTIO_BLK(vdev
);
877 while (qemu_get_sbyte(f
)) {
878 unsigned nvqs
= s
->conf
.num_queues
;
883 vq_idx
= qemu_get_be32(f
);
885 if (vq_idx
>= nvqs
) {
886 error_report("Invalid virtqueue index in request list: %#x",
892 req
= qemu_get_virtqueue_element(vdev
, f
, sizeof(VirtIOBlockReq
));
893 virtio_blk_init_request(s
, virtio_get_queue(vdev
, vq_idx
), req
);
901 static void virtio_blk_resize(void *opaque
)
903 VirtIODevice
*vdev
= VIRTIO_DEVICE(opaque
);
905 virtio_notify_config(vdev
);
908 static const BlockDevOps virtio_block_ops
= {
909 .resize_cb
= virtio_blk_resize
,
912 static void virtio_blk_device_realize(DeviceState
*dev
, Error
**errp
)
914 VirtIODevice
*vdev
= VIRTIO_DEVICE(dev
);
915 VirtIOBlock
*s
= VIRTIO_BLK(dev
);
916 VirtIOBlkConf
*conf
= &s
->conf
;
920 if (!conf
->conf
.blk
) {
921 error_setg(errp
, "drive property not set");
924 if (!blk_is_inserted(conf
->conf
.blk
)) {
925 error_setg(errp
, "Device needs media, but drive is empty");
928 if (!conf
->num_queues
) {
929 error_setg(errp
, "num-queues property must be larger than 0");
932 if (!is_power_of_2(conf
->queue_size
) ||
933 conf
->queue_size
> VIRTQUEUE_MAX_SIZE
) {
934 error_setg(errp
, "invalid queue-size property (%" PRIu16
"), "
935 "must be a power of 2 (max %d)",
936 conf
->queue_size
, VIRTQUEUE_MAX_SIZE
);
940 if (!blkconf_apply_backend_options(&conf
->conf
,
941 blk_is_read_only(conf
->conf
.blk
), true,
945 s
->original_wce
= blk_enable_write_cache(conf
->conf
.blk
);
946 if (!blkconf_geometry(&conf
->conf
, NULL
, 65535, 255, 255, errp
)) {
950 blkconf_blocksizes(&conf
->conf
);
952 if (conf
->conf
.logical_block_size
>
953 conf
->conf
.physical_block_size
) {
955 "logical_block_size > physical_block_size not supported");
959 virtio_init(vdev
, "virtio-blk", VIRTIO_ID_BLOCK
, VIRTIO_BLK_CFG_SIZE
);
961 s
->blk
= conf
->conf
.blk
;
963 s
->sector_mask
= (s
->conf
.conf
.logical_block_size
/ BDRV_SECTOR_SIZE
) - 1;
965 for (i
= 0; i
< conf
->num_queues
; i
++) {
966 virtio_add_queue(vdev
, conf
->queue_size
, virtio_blk_handle_output
);
968 virtio_blk_data_plane_create(vdev
, conf
, &s
->dataplane
, &err
);
970 error_propagate(errp
, err
);
971 virtio_cleanup(vdev
);
975 s
->change
= qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb
, s
);
976 blk_set_dev_ops(s
->blk
, &virtio_block_ops
, s
);
977 blk_set_guest_block_size(s
->blk
, s
->conf
.conf
.logical_block_size
);
979 blk_iostatus_enable(s
->blk
);
982 static void virtio_blk_device_unrealize(DeviceState
*dev
, Error
**errp
)
984 VirtIODevice
*vdev
= VIRTIO_DEVICE(dev
);
985 VirtIOBlock
*s
= VIRTIO_BLK(dev
);
987 virtio_blk_data_plane_destroy(s
->dataplane
);
989 qemu_del_vm_change_state_handler(s
->change
);
990 blockdev_mark_auto_del(s
->blk
);
991 virtio_cleanup(vdev
);
994 static void virtio_blk_instance_init(Object
*obj
)
996 VirtIOBlock
*s
= VIRTIO_BLK(obj
);
998 device_add_bootindex_property(obj
, &s
->conf
.conf
.bootindex
,
999 "bootindex", "/disk@0,0",
1003 static const VMStateDescription vmstate_virtio_blk
= {
1004 .name
= "virtio-blk",
1005 .minimum_version_id
= 2,
1007 .fields
= (VMStateField
[]) {
1008 VMSTATE_VIRTIO_DEVICE
,
1009 VMSTATE_END_OF_LIST()
1013 static Property virtio_blk_properties
[] = {
1014 DEFINE_BLOCK_PROPERTIES(VirtIOBlock
, conf
.conf
),
1015 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock
, conf
.conf
),
1016 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock
, conf
.conf
),
1017 DEFINE_PROP_STRING("serial", VirtIOBlock
, conf
.serial
),
1018 DEFINE_PROP_BIT64("config-wce", VirtIOBlock
, host_features
,
1019 VIRTIO_BLK_F_CONFIG_WCE
, true),
1021 DEFINE_PROP_BIT64("scsi", VirtIOBlock
, host_features
,
1022 VIRTIO_BLK_F_SCSI
, false),
1024 DEFINE_PROP_BIT("request-merging", VirtIOBlock
, conf
.request_merging
, 0,
1026 DEFINE_PROP_UINT16("num-queues", VirtIOBlock
, conf
.num_queues
, 1),
1027 DEFINE_PROP_UINT16("queue-size", VirtIOBlock
, conf
.queue_size
, 128),
1028 DEFINE_PROP_LINK("iothread", VirtIOBlock
, conf
.iothread
, TYPE_IOTHREAD
,
1030 DEFINE_PROP_BIT64("discard", VirtIOBlock
, host_features
,
1031 VIRTIO_BLK_F_DISCARD
, true),
1032 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock
, host_features
,
1033 VIRTIO_BLK_F_WRITE_ZEROES
, true),
1034 DEFINE_PROP_END_OF_LIST(),
1037 static void virtio_blk_class_init(ObjectClass
*klass
, void *data
)
1039 DeviceClass
*dc
= DEVICE_CLASS(klass
);
1040 VirtioDeviceClass
*vdc
= VIRTIO_DEVICE_CLASS(klass
);
1042 dc
->props
= virtio_blk_properties
;
1043 dc
->vmsd
= &vmstate_virtio_blk
;
1044 set_bit(DEVICE_CATEGORY_STORAGE
, dc
->categories
);
1045 vdc
->realize
= virtio_blk_device_realize
;
1046 vdc
->unrealize
= virtio_blk_device_unrealize
;
1047 vdc
->get_config
= virtio_blk_update_config
;
1048 vdc
->set_config
= virtio_blk_set_config
;
1049 vdc
->get_features
= virtio_blk_get_features
;
1050 vdc
->set_status
= virtio_blk_set_status
;
1051 vdc
->reset
= virtio_blk_reset
;
1052 vdc
->save
= virtio_blk_save_device
;
1053 vdc
->load
= virtio_blk_load_device
;
1054 vdc
->start_ioeventfd
= virtio_blk_data_plane_start
;
1055 vdc
->stop_ioeventfd
= virtio_blk_data_plane_stop
;
1058 static const TypeInfo virtio_blk_info
= {
1059 .name
= TYPE_VIRTIO_BLK
,
1060 .parent
= TYPE_VIRTIO_DEVICE
,
1061 .instance_size
= sizeof(VirtIOBlock
),
1062 .instance_init
= virtio_blk_instance_init
,
1063 .class_init
= virtio_blk_class_init
,
1066 static void virtio_register_types(void)
1068 type_register_static(&virtio_blk_info
);
1071 type_init(virtio_register_types
)